The busiest land crossing from the US to Canada remained shut on Tuesday, Canada’s border agency said, after Canadian truckers blocked lanes on Monday to protest their government’s pandemic control measures.

Drivers demanding an end to federal Covid-19 vaccine mandates for cross-border traffic began blocking the streets of Canada’s capital, Ottawa, on January 28. Since Sunday night, police have started slowly taking back control, seizing thousands of litres of fuel and removing an oil tanker truck.

Trucks started blocking traffic at the Ambassador Bridge, located between Lake Erie and Lake Huron, late on Monday. Canada’s Border Services Agency said on Tuesday that the bridge was closed, but police later tweeted that US-bound lanes were now open.

The owner of the bridge, the Detroit International Bridge Co, said international commerce on the bridge needed to resume.

“We encourage the appropriate officials to take prompt action to alleviate the situation as quickly as possible in a manner that reflects mutual respect,” the company’s chairman, Matt Moroun, said.

Canada sends 75 per cent of its goods exports to the US, and the bridge usually handles around 8,000 trucks a day.

The president of the Canadian Vehicle Manufacturers’ Association called for an immediate end to the blockade, saying “persistent delays at the Ambassador Bridge risk disrupting automotive production”.